The staff structure in Japanese and German coking plants is introduced.The per capita coke production capacity of Kakogawa Coking Plant of Kansai Thermo Chemical Co.,Ltd.is 7 843t/a.The per capita coke production capacity of Schwelgern Coking Plant is 8 667t/a.
By analyzing the problems occurred during heating with BFG,the factors influencing the uniformity and stability of coke oven temperature are found out.Comparing the longitudinal temperature of JN60-6 type coke oven heated with BFG with the NOx content measured online at the coke oven chimney,a scheme for oven temperature control according to the NOx content monitored at coke oven chimney is proposed.The problem of delay by manual regulation of the oven temperature is solved.
Temperature decreasing features and measures to be taken during shut down of coke oven are introduced.Without external heating,measures such as sealing and insulating are taken during cooling down to slow down the cooling speed,so that damage to the coke oven brickwork can be reduced.
This paper introduces the technology of water seal type dedusting station on P.S.,i.e.U-tube water seal type P.S.dedusting station is adopted for No.5 battery of MaSteel,which is a solution to dust pollution while pushing and leveling on pusher side for top-charge battery.
The feasibility of a new technology for accurate online measurement of the coefficient of excess air α during coke oven heating is studied to explore a method and model to guide and improve the adjustment of coke oven heating system timely and quantitatively,so that gas can be completely burnt,and energy can be saved.
By comparing the advantages and disadvantages of fixed time maintenance and fixed oven number maintenance，and based on the actual application of these modes on 7m coke oven battery，this paper discusses the influence of maintenance mode to the operation of coke oven and demonstrates the advantages of fixed oven number maintenance during operation of coke oven battery.
Based on the production conditions of CDQ system，the high temperature measuring device overcomes the negative factors such as high temperature emissions and realizes online detection，image formation and chamber condition analysis，providing a sound foundation for the regular and annual maintenance of CDQ chamber.It brings remarkable economic benefit.
The upper large springs are subject to the weather,oven temperature and mechanical change during normal operation,so the load change varies in a wide range.The factors causing the change are found out,providing a sound foundation for the stable,continuous and efficient production of coke oven battery.
The overall structure,system capacity and features of the high level 8-cylinder hydraulic reversing machine are introduced.With its application on large scale coke oven battery,the production automation level is improved,providing a sound foundation for further improvement on automatic operation of coke oven battery.
The energy consumption of coal handling system of different design capacity is calculated，and the system capacity with minimum energy consumption is obtained. The energy recycling and utilizing during coal storage and processing，and solid waste innocent treatment process are calculated to provide data support for design optimization.
With comparison of the coke produced from the 7.63m coke oven battery of Shasteel,the properties of the coke produced with addition of DK additive in OAO NLMK Iron & Steel Company in Russia is studied.The result shows that the quality of coke produced in OAO NLMK is not as good as that produced in Shasteel.There are more fragment structures in the microstructure.Alkali metal content in ash is higher.CRI of coke and graphite degree are higher.
Based on the field survey and numerical simulation, the reason for the failure of CDQ tube heat exchanger is analyzed. Specified optimization suggestions are proposed.
In this paper，the deactivation of the hydrogenation catalyst with reaction time is studied by hydrogenation of high temperature coal tar over the micro-fixed bed reactor.The regeneration effect of high temperature calcination method and solvent washing method is studied and analyzed，based on which a suitable method for catalyst regeneration is finalized.
The effects of a series of Lewis acid catalysts on the activation of naphthalene ring under mild conditions are studied.The results show that Lewis acid FeCl3,AlCl3 and ZnCl2 exhibit good catalytic activity in the hydrogenation of naphthalene,and ZnCl2 can activate the naphthalene ring to the maximum extent,with a high yield of tetrahydronaphthalene.
Take one project for comprehensive use of coal in Xinjiang as an example，the process proposals before and after technical renovation are analyzed.Consumption of public utilities are calculated.The overall economical efficiency of the renovation is evaluated.
Take the waste heat of the coking process as the study object，with the use of advanced technology，and through establishing a matching relationship of energy coupling，the waste heat can be recovered and utilized，so that the energy utilization efficiency is improved a lot.
Chemical oxygen demand is an important index for evaluating the degree of pollution of water.It is an important parameter to monitor water quality.This paper analyzes the advantages and disadvantages of potassium dichromate method and spectrophotography method,based on which the measuring method for determination of coking waste water is improved.
A series of technological innovations have been implemented,including automatic regulation and control of the temperature on the top of benzol stripper,improvement of slag discharge of the vacuum debenzolization system and cleaning the final cooler without shut down,so the vacuum debenzolization process is optimized,bringing significant effect in energy saving and emission reduction.
This paper describes the importance of desulfurization of coke oven gas,and introduces HPF desulfurization process and FR desulfurization process.Based on the experiences in actual production,we combine HPF process and FR process and develop a“short column” HPF desulfurization process to make use of their advantages.The new design shows better effect in desulfurization.
Using the process data measured at plant site,and based on the steady state detection,clustering analysis and the model of heat exchange,a steady-state identification method for tubular furnace in crude benzol distillation unit is proposed to effectively identify the tubular heating furnace model.The effectiveness of this method is proved by the test of identification mode based on the actual data of a coking plant.
The vacuum crude benzol distillation with lean gas heating in the tube furnace instead of steam and the vacuum crude benzol distillation with steam are introduced.The influence of foul gas to the vacuum crude benzol distillation process，to the area of crude benzol condenser and cooler and to the power of vacuum pump is introduced, and measures to reduce foul gas concentration are proposed.
The sensible heat and effective energy of saturated steam and superheated steam are studied and compared.Saturated steam is mainly used for heat exchange, while superheated steam is mainly used for power generation, drying and long distance transportation.
The schemes of improving tar yield and quality by lignite pre-treatment are discussed.The advantages and disadvantages of different pre-treatment schemes are compared.Thermal pre-treatment and solvent swelling pre-treatment are easily to be industrialized.The development of ionic liquid pre-treatment is introduced.With this method,the pyrolysis tar yield and light tar yield can be remarkably increased.
The function of Gieseler fluidity in guiding coal blending for coking is analyzed.The result shows that the individual coal can be quickly identified by Gieseler fluidity.There is obvious correlation between the maximum degree of fluidity and caking index，plastometer indices and maximum reflectance of vitrinite.The Gieseler fluidity and temperature shall be taken into consideration during coal blending.
To meet the requirement on coke quality of large scale blast furnace,the influencing factors of coke screening and transfer system on coke grain size are analyzed.It is found that the coke grain size can be increased by controlling the coke charging flow,increasing the area receiving coal,coke screening flow control and coke charging at low level.
The reasons for the damage of the water seal tank on the top of CDQ chamber are analyzed.By improving the structure of water seal tank and adding high temperature resistant and inflaming retarding and thermal insulating material,the overall rigidity and thermal endurance of the water seal tank are improved,the service life of spare parts is extended and the equipment cost is reduced with an annual economic benefit of 556 000 Yuan/set.
The structure of a recirculating water tank with the function of automatic purification,its usage and recycling principle are introduced.With application of such water tank,about 40 000t/a of water can be saved for each set of CDQ water sealing system.The effect of water saving is remarkable.
By analyzing the relationship between the steam output of CDQ and air flow,temperature and apparent heat of coke during actual production,the factors influencing the output of steam are found out. Corresponding adjustments are made to improve the steam output of CDQ plant.
The generation and harm of water hammer effect of coke wet quenching system are introduced.The hammer effect which occurs during shut down of the quenching pump is controlled by soft starters under different control mode.The result shows the pump-controlled soft starter can realize soft shut down of the quenching pump,and so it can effectively overcome the problem of water hammer effect of the coke quenching system.
The reasons for the ash accumulation in the CDQ boiler pipe and the harm to production are analyzed.The working principle of sonic soot blowing,the composition and features of sonic soot blower of high sound intensity and adjustable frequency,its application on CDQ boiler and actual effectiveness are introduced.
If the heating wall of coke oven battery is first repaired and then heated up under hot state,the adjacent heating wall and the wall surface not repaired will be damaged more quickly.Regarding to this problem,the revamping-heating technology is adopted to repair the heating wall while heating up.The expansion joint of silica bricks can be determined according to the temperature.With this technology,the repair effect is satisfying.It is of great significance for coke oven maintenance under hot state.
Bracing system management and temperature monitoring during protective cooling down of coke oven battery are introduced.Protective cooling down is to provide more protective force to the oven wall by increasing the load of springs,so that the temperature decreasing rate of the battery proper is slowed down effectively.
The application of DCS S7-400 in the production control system of 7.63m coke oven battery,and the system structure,control philosophy,and man-machine interface of the whole automatic control system are introduced in this paper.DCS system can overcome the difficulties in data collection and mangement,complicated sequential control,safety interlocking and stable and reliable communication with other devices during the production of large scale coke oven battery.The field equipment can be monitored and controlled accurately in the center control room.
The personal injury accidents in the past six years in a Steel Complex are statistically analyzed.The result shows that the design of traditional coke oven battery needs to be optimized,reserving enough space for safe arrangement of platform,rail and passway,and the production equipment has to be advanced.
To solve the problem of floating coke in the corbel zone of CDQ chamber,a new partition type corbel zone structure and auxiliary technologies are adopted.Compared with the single channel corbel zone structure, the flow of circulating gas is reduced by 30%.The resistance in the chamber is reduced, and there is no floating coke in the corbel zone.Therefore, the capacity of CDQ chamber is increased by 40%.
The pressure of gas collecting main (GC main) is one of the control data for coke oven production.The method to determine the control value of GC main pressure is studied.By using a new type of electronic manometer,the pressure of GC main and at the bottom of coking chamber is measured,based on which the control value of GC main pressure is finalized.
Based on the features of coke oven flue gas,the denitrification catalysts having the properties of good activity,sulfur resistance and water resistance under low temperature are studied,guiding the development of denitrification catalyst for coke oven flue gas.
The development status of anthracene oil hydrogenation projects in China is introduced,the technology development of heavy oil hydrogenation is summarized,the marketing situation of anthracene oil hydrogenation products is analyzed,and the future development of the projects is discussed in this paper.
The citrate process for SO2 removal from the flue gas by multistage absorbing-desorbing is introduced.The SO2 obtained via this process can be reused as resource together with the typical resources of the coking enterprises.
With the use of existing waste water treatment facilities,by increasing the concentration of the activated sludge in the aerobic tank,the load of sludge is reduced,stable operation of the biochemical treatment system can be ensured,and the waste water treatment effect is improved.
With adoption of regenerative combustion furnace, the heat efficiency of coal tar processing waste gas treatment is higher than 96%.By waste gas pre-treatment and burning, the average purification efficiency of pollutants is above 95%.It has the features of high purification efficiency, broad application range and stable operation.
The two-conversion two-absorption sulfuric acid making technology，the features of sulfur slurry produced by FR desulfurization unit,process gas and the main problems found during operation and corresponding solutions are introduced.This technology is technically evaluated in this paper.
Two typical HPF desulfurization processes are introduced,and improvements have been made for high tower regeneration process and jet-oxidation regeneration process.These two processes are compared in the aspects of investment, energy consumption,land occupation and operation stability.The result shows that high tower regeneration process has the advantages of good regeneration effect,high operation stability,while jet-oxidation regeneration process has the advantages of less investment and land occupation.
After a long time study of the acidity and temperature of ammonium sulphate mother liquor,improvements are made on the preparation of the mother liquor by stopping the gas pre-heater,and utilizing the recycled hot water.With such improvements,the steam consumption is reduced,the ammonium sulphate quality is improved and the output is slightly increased.
The problem of blockage in the tail gas pipeline of tar distillation vacuum system is analyzed,and it is found that the main reason for the blockage is ammonium salt.By replacing the washing liquor methylnaphthalen with warm water,and improving the operation conditions,the problem of blockage in the tail gas pipeline of tar distillation vacuum system is solved.
The 1/3 coking coals from Henan and Shandong are analyzed and compared.The result shows that blending of Henan A mine is good for the fluidity and dilatation,and the coarse mosaic texture is much more than Shandong B mine.The coking microstructure of single coal of 1/3 coking coal in B mineral is mainly fine mosaic structure.Higher blending ratio of it will worsen the coke quality.For the coking coal with similar caking index and maximum thickness of plastic layer,that with better fluidity and dilatation properties is good for the improvement of coke quality.
By comparing the coal properties and result of blending fat coal from Shangdong A mine and Shangxi B mine,it is found that the volatile matters,fluidity and fine mosaic structure for coking of fat coal from Shangdong A mine are higher.Blending of it within certain range of ratio is good for improving the abrasion resistance of coke,but too high percentage of it will weaken the hot strength of coke.The fat coal from Shanxi B mine has more coarse structure for coking,but its fluidity is poor.Less blending of it is not good for the abrasion resistance of coke,so the coke abrasion strength can be improved by increasing its blending ratio or blending a certain amount of gas fat coal.
The fine intelligent coal blending system is introduced.The pilot test and industrial test results show that the quality of coke produced from coal blend with a proportion ratio provided by the fine intelligent coal blending system meets the production requirement.Coal blending cost is reduced.It is suitable for the prediction of different oven types,and the prediction result is precise.
The proper and process equipment of CDQ are improved and optimized by increasing the volume of prechamber,adopting double flue technology,improving the performance of refractories,optimizing the charging device,modifying the secondary de-duster and optimizing the crane system.After improvement,the temperature of discharged coke is reduced to 140℃,the utilization rate of waste heat is increased,and coke supply to the blast furnace can be ensured.
Based on the coke quality data of Shaogang in 2016,the coke quality prediction model was established with data analyzed and treated by regression method.This model is applied in the production and sale system developed by Shaogang,so that the coke quality can be automatically predicted.This provides a theoretical basis for optimizing coal blending structure and decreasing coal blending cost.
Coke sample was taken from the air inlet of the 2 500m3 blast furnace in Shagang.The ash content,grain size,optical texture,degree of graphitization,reactivity and maximum bearing pressure were determined.The quality of the coke at the air inlet and the coke charge was compared.The study shows that the smaller the grain size of coke at air inlet,the higher the reactivity and degree of graphitization,the abrasion of the surface texture of the coke at the air inlet is more serious,the reaction layer is thinner,the compression strength doesn’t change,surface abrasion resistance is lower and the surface is easily pulverized.
Coal blending & coking test is carried out with a 40kg pilot coke oven,which can provide the optimum coal blending ratio as a guidance for coke production.In case the coal source is not stable,and there is a shortage of good quality coal,the pilot coke oven can provide sound foundation for optimum coal blending and comprehensive utilization of coal resources.
The current status of coke burning loss of the coking system is introduced,and a method is proposed to determine the coke burning loss of the coking system and CDQ system.The coke burning rate can be reduced and economic benefit can be increased by improving the tightness of the system and optimizing the process operation conditions.
This paper points out the disadvantages of conventional way of breakdown compensation for JN60-6 coke oven battery,and proposes a new method for breakdown compensation,i.e.alternate wet and dry coke discharging method,which can improve the compensation efficiency and the output of coke and reduce energy consumption.It provides a technical reference for the production recovery after maintenance for coke oven batteries of the same type.
The fixing rod of fixing cup of PROven system of 7.63m coke oven has broken several times，causing negative pressure in the coking chamber.As a result，the system cannot be controlled automatically.Through study and analysis，it is observed that the main factors causing the breakage is abrasion and corrosion.After improvement，the fixing rod is more stable，with slight vibration and less abrasion.The problem of fixing rod breakage is effectively avoided.
The reason for the vibration failure of CDQ circulating fan is analyzed through frequency spectrum.It is found that the failure is caused by unbalanced rotor.The rotor is timely replaced，and during the replacement，it is found that there are many abrasions and cracks at the root of rotor blades.This verifies the judgement for the previous failures.Therefore，more serious accident such as broken of rotor blades can be avoided，and the purpose of predicative maintenance can be achieved.
The dynamic pilot test of coke oven battery shows that with adoption of salt bath coil structure,the inner wall surface temperature of heat absorber on the ascension pipe of coke oven battery can be controlled,and the tar vapor contained in the raw gas will not condense.During the whole coking period,the inner wall surface temperature of heat absorber,total heat exchange coefficient and the radiation heat exchange coefficient of the coking chamber are stable at the early stage,and decrease at the late stage.The radiation heat exchange coefficient of raw gas and the radiation heat exchange coefficient of the coking chamber decrease as the height increases.
The water condensing system and direct air condensing system for turbine power generation are introduced, and the operation parameters of turbine power generation station in CDQ project are analyzed.The two systems are compared from the aspects of generation capacity,power consumption, investment,land occupation and running cost.
Generally double-loop water feeding system is adopted for supply of boiler feed water.The advantages and disadvantages of double-line feed water system and single-line feed water system are compared.Some suggestions are provided to adopt the single-line feed water system.
The process of waste heat recovery and utilization from the waste water of CDQ boiler is introduced.With adoption of this process, the problem of deformation and cracks on the water seal tank can be effectively solved.Therefore, the service life of water seal tank is extended, and the production cost of CDQ is reduced.It is an effective way to save energy and reduce waste discharge.
The classification of coking waste gas and corresponding treatment technologies are introduced. The advantages and disadvantages of different treatment technologies are described in detail, and suitable suggestions are proposed based on practical engineering experience to improve the technologies.
An online repair method for the broken shaft of oven door service car is introduced.Online repair has the advantages of short repair time and high efficiency.It can greatly reduce the production cost and bring remarkable economic benefit.
Coke oven gas is an importation energy and chemical raw material.The current general utilization of coke oven gas is introduced.It is proposed that coke oven gas polyregeneration is one of the methods to fully make use of coke oven gas and maximize the economic benefit.
The principle and application of a new catalytic oxidation desulfurization process is introduced.Compared with other desulfurization processes,it has the advantages of good desulfurization effect,less consumption of desulfurizer,and no secondary pollution.
By simulating the phenol removal process in the laboratory，the influence of reaction time，reaction temperature，density and flow of NaOH on the dephenolization efficiency，the influence of settling time on neutral oil content in phenol salt，and the influence of different light oil on the washing result of phenol salt are studied.Based on the result the optimum process conditions are finalized for fraction dephenolization.On the basis of experimental data and the actual condition at site，the process operation data are optimized and adjusted.After improvement，the dephenolization efficiency of phenol oil，naphthalene oil and washing oil is increased by 3.7%，2.6% and 4.9% respectively.The neutral oil and free alkali are decreased by 48% and 37% respectively.
The number of cooling is an important factor in the thermal calculation of cooling tower.The study shows that the number of cooling is closely related with environment,climate,supply water temperature and water temperature at outlet.It has nothing to do with the parameters of packings,circulating water flow or ambient atmosphere.
Coal tar is normally processed under high temperature.The temperature of recovered anthracene oil is up to 220℃,so it is very important to tightly seal the pump.After studying the sealing method and implementing renovation to the anthracene oil pump,the pump shows good performance.
As the raw oil has been at a low price for a long time,the coal chemical hydrogenation plant is facing the problem of deficit as soon as being put into operation.Based on the analysis of industry and enterprise condition,the products of coal chemical hydrogenation plant and purchase of raw materials are expatiated,and the suggestions of product differentiation and refinement and improvement on raw material purchase network are proposed.
By analyzing the reactivity of metallurgical coke in different areas of blast furnace,a new understanding is concluded on the thermal property of metallurgical coke.It indicates that the current measuring method for coke reactivity and CSR is not suitable for blast furnace simulation.A more reasonable measuring method is discussed to stabilize blast furnace operation and control the coke quality properly.
Ash composition in coking coal is analyzed in this paper,which can be used as a reference for procuring and using the coking coal,and can allow an optimization of coal blending ratio,reduction of alkali metal in coke,stabilization of coke quality and improving hot strength of the coke.
In this paper, processes of CMC and pre-drying for gasification are introduced and comparison is made in aspects of process flow and auxiliary facilities.
A method of evaluation on cost performance of coking coal by using mathematical model is introduced.The cost performance is calculated in a mathematical model,according to which sequence can be arranged for the evaluation so that the superior coking coal can be selected and the inferior one can be eliminated.Therefore,the procurement cost and blending cost can be dramatically lowered.
Comparison of NOx generation mechanism and production data between heat recovery coke oven and normal coke oven
The NOx generation mechanism of heat recovery coke oven and normal coke oven is introduced. The waste gas of heat recovery coke oven contains less NOx, and can be discharged directly, so heat recovery coke oven is more environment friendly than normal coke oven.
Safety precautions and accident preventions are introduced in this paper against risks in 7.63m coke oven operation,such as mechanical injury,gas poisoning,explosion,etc..Solutions and improvements are proposed regarding to the potential risks in production,such as lining bricks damage in the ascension pipe,gas leakage in the cellar,and optical fiber problem in the elevator,and so on.
Introductions are given for the configuration of hot coke emergency water spraying system and selection of water feeding control valve.Optimization is also done based on the original piping arrangement and water feeding system to protect belt conveyor against damage which may occur due to excessively high temperature of the not well quenched coke so as to ensure safe production for the CDQ system.
Design deficiency of adjusting structure for the existing side pressurizing spring for oven door knife edge is analyzed in this paper and an optimized knife edge cap spring structure is introduced.Tar jamming and rust occurred in screw plug and the screw thread can be avoided so that easy routine maintenance is possible at low cost and in an environment-friendly way.
The factors causing excess error of coking repeatability test is analyzed.It is found that the main factors are coal blending and coke quenching.Methods for reducing the error are provided.With adoption of improvements on operation,the error is controlled within the required standard.
By installing an auxiliary heating system for the end flue of 7m coke oven,the problems of hot coke adhering on the bucket,poor uniformity of coke quality,too much smoke when lifting oven door,and high heat consumption during coking caused by low temperature of end flue are solved.This system has the advantages of less investment and simple operation.The improvement is remarkable,so it has promising potential for market development.
On the basis of blending more anthracite for coke making,a 40kg pilot coke oven is used to study the optimum coal blending ratio to produce coke with high CSR.The result shows that with 30%~40% anthracite and 50%~55% coking coal and fat coal blended,the stamp-charging coke oven can produce coke with CSR higher than 60%,and both the mechanical strength and CSR of coke meet the requirement of first class metallurgical coke.
Analysis is made for the change of water quality before and after wet quenching by testing different waste water sources.The result shows that a finite concentration of waste water used as wet quenching source can not only ensure a stable operation for the quenching process，but also minimize the pollutants in the waste water，which is proved a better solution than using clean fresh water.
The content of cyclopentane in the byproduct of hydro-refining-non-aromatic hydrocarbon is very high,which is about 33% by weight.First the cyclopentane is extracted from the non-aromatic hydrocarbon,and then the impurities are removed by molecular sieve and activated carbon to obtain high purity cyclopentane.
The problems of vacuum potassium desulfurization and acid-making process introduced and analyzed. After improvement on the process,the problem of tail gas pollution is solved,and the negative influence of waste alkali after desulfurization to the waste water treatment system is avoided.
Based on the analysis of heat exchange network of tar distillation system,the pinch temperature is worked out with pinch technology.The operating status of the heat exchange network can be evaluated in a scientific way.The heat exchange between cold and hot materials is optimized to improve heat exchange efficiency.The annual cost can be cut down by 830 000 Yuan.
A method to prepare isotropic coke using coal pitch as raw material is introduced.The process combines the pretreatment of isotropic coke and anisotropic coke.This method mainly lies in the preparation of raw materials and selection of coking process data.
The process of phenol-cynaide-containing waste water treatment in coking plants is introduced.The reasons for the high ammonia nitrogen concentration in waste water after bio-chemical treatment of phenol-cynaide-containing waste water are analyzed.Based on the analysis result,improvement measures are taken,after which the ammonia nitrogen concentration meets the design requirement.
The difference between heat supply unit and full condensing unit is analyzed.Advice is provided for cold end optimization.Cold end optimization of the heat supply unit shall consider heating season and non-heating seasons repectively.The influence of backpressure on heat consumption during heating season is less,so the designed backpressure shall be determined based on the climate conditions of non-heating seasons,cold end arrangement and running time of the unit. Co-generation of heat and power; Heat supply unit; Designed backpressure
Process optimization is made to solve the problems of high resistance in the system,poor product appearance and frequent maintenance during the production of ammonia sulfate with the saturator.After optimization,the product quality is improved,maintenance frequency is reduced and the system resistance is lowered,The result is as good as expected.
The current utilization of coking steam condensate is introduced.Several energy saving measures are taken to recycle the condensate for comprehensive utilization.The energy saving result is remarkable，and the operation environment is improved.
Three ammonia vaporization processes,liquid ammonia vaporization,ammonia liquor distillation and concentrated ammonia liquor vaporization,are introduced and compared with respect to process features,project investment,media consumption and operating cost.It provides a reference for selection of ammonia vaporization process.
Processes of coke oven flue gas desulfurization and denitrification are introduced in this paper,as well as their integration technology combined in one equipment. Advantages and disadvantages of each de-SOx and de-NOx process at present are also summarized,which plays a directive role in this technology development.
To meet the requirement of reducing ash content in coke by Masteel,13 kinds of coal blending schemes are determined based on each individual kind of coal from Huaibei coal mines,which have been washed and selected into different ash contents by coal dressing method.The blended coal quality and the coke quality produced from 40kg test oven are analyzed. The result shows that the blended coal ash content,ash catalytic index and caking property vary with the ash content of Huaibei coal,in which the Huaibei lean coal ash content decreases,and the coke quality increases accordingly.
By coal analysis and coke property test,the possibility of Xinzhou-produced gas coal replacing Fengfeng 1/3 coking coal is studied, including the best proportion.The test result shows that the Xinzhou-produced gas coal is an ideal substitute of Fengfeng 1/3 coking coal, its usage proportion is preferably controlled within 6% when the coke strength in hot state drops down very little,which can ensure a supporting bed in blast furnace.
Three kinds of coals with different metamorphism degree are studied for determination of coal grindability indices under different moisture.The result shows that the coal grindability indices are mainly related to metamorphism degree,i.e.there is a linear relation but not much between the coal grindability indices of different metamorphism degree and the moisture.
The feasibility is studied for reducing energy consumption in producing per ton of coke by increasing the cross wall coefficient for 7.63m coke oven.By stabilizing heating system,adjusting injecting plate and replacing checker brick,etc.,the uniformity of cross wall temperature can be improved,the cross wall coefficient can be increased and energy consumption for producing per ton of coke can be reduced.
The differences between CDQ boilers of high temperature plus high pressure and that of medium temperature plus medium pressure are introduced in aspects of design parameter and structure.Comparison is also made in respects of water quality,air\|fuel ratio,vaporization rate and circulating gas,etc.based on the actual operating parameters of the CDQ boiler in Baosteel.In addition,analysis is made for the related differences in design for the CDQ boiler.Suggestions are also given for improving Baosteel CDQ boiler operation in the future.
The causes of damage to the PROven fixed cup are analyzed.Solution to the fixed cup maintenance in a safe manner is proposed so that the frequent damage to the fixed cup can be effectively solved and safety risk in maintenance can be minimized.
The high efficiency integration technology of waste heat recovery of coke oven ascension pipe gas is introduced.The performance of this technology is beyond the requirement of national standards,and the steam output is 27% higher than the requirement of national standards.The system can run stably and show good application effect.It can bring remarkable economic benefit.
The cause of door frame deformation for 6m coke oven is made.Solution is also given that the deformed door frame of empty coking chamber can be on\|line replaced in hot state which not only prevents the oven door from emission polluting due to poor sealing caused by door frame deformation,but also avoids the deformation on the bracing system such as tie rods,buckstays,etc.burnt by the flame.
CDQ bucket car locomotive technology for 7m coke oven is introduced in this paper.Improvement and optimization have been done for the problems and defects in production by modifying equipment and adjusting parameters,etc.so as to ensure a stable operation for the CDQ locomotive.
In this paper,working condition of 15MW condensing type turbine is analyzed.Fouling at turbine nozzle,the main cause of low efficiency is found.Three measures i.e.steam purging,hot water cleaning and cylinder-removal cleaning are given,including each feature,which can be selected according to actual situation.
Electromagnetic vibration feeder in CDQ unit and its internal structure are introduced in this paper.The steps for the coil replacement are described.The causes of burnt coil in the feeder are analyzed and preventive measures are also given.
Regarding to the problems on gas pipe during heating of coke oven,the reasons for water and gas leakage of the pipe are analyzed and concluded,based on which proposals are made to prevent corrosion of gas pipe.It can be used as a reference for other plants.
The process flow,interlock control and index requirement of the coke oven flue gas De-SOx & de-NOx system and waste heat recovery system are introduced.The structure and configuration of DCS as well as hardware configuration are designed in detail.The flue gas after treatment can meet the requirement of GB 16171—2012 Emission Standard of Pollutants for Coking Chemical Industry.
The temperature of raw gas at the outlet of gas collecting main is a key parameter for calculating cooling water demand and designing the primary cooler.By analyzing the cooling process of raw gas,a cooling model for the raw gas in the gas collecting main is established.The influence of dry coal water yield,clean gas yield,inlet temperature and outlet pressure of raw gas on the temperature of raw gas at the outlet is quantitatively analyzed.The outlet temperature of raw gas rises with the increase of dry coal water yield and raw gas pressure at the outlet,but it decreases with the increase of clean gas yield.
Based on the first principle of Density Functional Theory(DFT),the absorbability of H2S and HCN,the main corrosive substance in COG on Fe-based surface are analyzed as well as the bonding situation after reaction between the corrosive molecule and the basal body.The energy of adsorption and partial density of states are also calculated.The result shows that the interaction between H2S molecule and Fe appears more intensive than the HCN molecule,which indicates the H2S in COG is much more corrosive to the Fe-based surface.
Regenerative thermal oxidizer (RTO) is adopted to deal with the coking waste gas.The process of RTO unit is optimized.The result shows that the coking waste gas after treatment by RTO can meet relevant requirements of national standards.The purification rate of organic gas is up to 99%,which is a quite satisfying result.
Solvent extract-continuous settling process is adopted in the pre-treatment unit for the production of needle coke.This process has the advantages of high yield rate of refined pitch,stable quality and less consumption of solvent.However its drawbacks of blocking the settling system cause the system hardly run for a long time.The factors influencing the ratio of aromatic hydrocarbons to fatty hydrocarbons,solvent ratio and settling time are analyzed respectively.
The technology of “advanced oxidation process+desalination+ultrafiltration+reverse osmosis” is adopted for the advanced treatment of coking waste water.The quality of the waste water after treatment is better than industrial water.It can be used as make\|up water for regulation pond and circulating cooling water,so it brings good environmental and economical benefits.
With adoption of gas chromatography method to measure the content of naphthalene and methylnaphthalene in washing oil,the sample can be used and separated directly without pre-treatment.The peak area of each composition is determined first,and then the percentage of each composition can be calculated by area normalization method.
With a coking plant as an example and with petroleum oil sample leaking from tar tank as pollutant agent,a prediction is made by adopting analytical method for determining the pollutant shifting in the groundwater and area of influence under abnormal working condition.The result shows that the analytical method turns out to be rational and practical,which can be used in a scientific way and as theoretical basis to protect groundwater against pollution.
Mathematical simulation is done for ammonia stripping process by using Aspen Plus.A comparison is made between the simulation result and the actual value of Baosteel Zhanjiang plant.No deviation is found which proves that the model is correct and valuable both theoretically and practically.
A method of superheated steam flow calibration suitable for PLC program algorithm is proposed in this paper.Its principle is to make a fitting for the superheated steam density table by polynomial surface fitting algorithm and to convert it into a fitting formula based on PLC programming so as to obtain a more precise fitting.The test result shows that this method has higher precision,wider range of application,and much simpler in expression,suitable for PLC programming compared with the conventional empirical method.It has been adopted for several projects with satisfactory results.
In experience of reviewing technical journals,the problems in manuscript papers submitted are analyzed,topic selection and wiring logic in the technical journals are discussed,the importance of logical thinking in the paper writing is demonstrated,which would provide references and clues in writing this kind of papers.It is well known that logical thinking plays a directive role in writing,much attention therefore shall be paid to the logical thinking in writing the technical papers so that academic level and writing quality can be upgraded by grasping correct topic selection and writing skills.
Coal source can be fixed based on determination for each quality index of the candidate sources.Cokemaking tests for several coal blends are also conducted by using experimental oven.The optimized coal blending composition for PW-7.2m top-charge coke oven can be decided since the coke quality can meet the requirement of 5 100m3 blast furnace production.
Properties of gas coal from different coal mines are analyzed by comparing the coal qualities of similar value G and Y.Coal blending test for cokemaking is conducted to study the differences in coke properties produced from gas coal.The result shows that coal vitrinite reflectance,logarithm of fluidity degree and plastic zone of fluidity play a dominant role in hot strength of coke.Since the gas coal has high plastic mass,good fluidity and high reflectance,it can appropriately be increased during coal blending.
The major problems in charging operation for 7.63m coke oven are analyzed.Optimization for 7.63m coke oven smokeless charging is put forwarded in aspects of charging amount calculation,coal leveling control mode,secondary make-up setting,charging time control,and leveling bar optimization so that production can be improved,such as a stable charging operation,increased charging amount,less spillage coal amount,stabilized coal line and minimized emission leakage.
This paper studies the intrinsic law and characteristics of coke micro pore structure by introducing fractal theory so as to demonstrate the correlation between the coke CRI and fractal dimension variation.The coke pore structures before and after reaction are measured by adopting mercury penetration method so that the coke micro pore structure change due to CO2 erosion can be analyzed and a new solution to the coke melting is given.
A suitable hot repair method can be selected for stamp-charge coke oven based on the experience of using several hot repairs with aims at solving the problems in the stamp-charge coke oven, such as serious erosion and penetration on the heating wall so that a stable and satisfactory production can be ensured.
Conventional and optimized replacement for water jacket for 200t/h CDQ unit are discussed.The optimized solution for replacement can be cut down to 36 hours,much shorter than the conventional solution.Besides,it has less man power,higher efficiency and much lower safety risk.
Obstacles affecting 2# CDQ unit production are introduced.The dry quenching rate for 2# CDQ unit is calibrated on site,including technical modifications.The modified 2# CDQ unit has a lower temperature of the coke discharged,uniformly distributed coke and higher coke discharging capacity,etc.,with dry quenching rate increased from 88.68% up to more than 93%.The CDQ capacity is gradually increased.
The cause of 2# CDQ boiler tube bursting in Coking Plant of Xinyu Iron & Steel is analyzed.Its preventive measures are also given，such as by stabilizing the boiler operation，improving chemical dosing，controlling demineralized water quality and periodically doing maintenance for the boiler，so that the CDQ unit can run in a stable manner.
In this paper a solution of capacity expansion and performance improvement for 140t/h CDQ unit is introduced.After the expansion,the CDQ unit would have a capacity up to 150t/h;with increase of flue numbers in the CDQ chamber,the corbel zone would have a longer service life;upon replacement of the chamber-top water seal pot,charging device and cooling jacket,etc.,its performance can be improved.
Manual unloading spillage coal procedures for 7.63m coke oven pusher machine are introduced.Interlock conditions of unloading the spillage coal are also analyzed in this paper.Automatic spillage coal unloading operation can be realized by writing program for elimination of hidden danger as well as for higher working efficiency and automation level.
Scheme and technical advantages of on-line analyzing system for coke grain size grade are described,including its all functions.This system is widely used,which plays a prominent role in improving safety and automation level.
Tubular belt conveyor would have tube expanding at the end during coal conveying if it is overloaded.For stable operation,the upstream of the tubular belt conveyor is equipped with material flow limiting device to control the volume of passing material no exceeding the effective volume of the conveyor for safe purpose.
In view of the fact that deSOx and deNOx devices change waste gas flue suction, it may cause influence to the coke oven heating system.This paper studies how to ensure safe and stable operation of the coke oven heating system in case of failure of deSOx and deNOx blowers and proposes a solution.
Acidmaking technology in treatment of low purity sulfur and secondary salt waste liquor by adopting “rich oxygen combustion” and “twice conversion & twice absorption” processes
This paper introduces a new H2SO4 making technology by adopting “rich oxygen combustion” and “twice conversion & twice absorption” processes in treatment of low purity sulfur and secondary salt waste liquor produced from COG desulfurization by wet catalytic oxidation. Operating conditions after commissioning are also introduced.
In case serious blockage and high resistance in the primary cooler would cause low efficiency for naphthalene removal in gas purification system.This paper introduces the solutions such as by upgrading process and by optimizing operation,etc.to improve the naphthalene removal efficiency for the primary cooler so as to ensure gas delivery in a safe way.
In this paper processes of COG desulphuration and decyanation are introduced and the principle & process flow of NNF method desulphruization and decyanation are described.The features and advantages of this NNF process are summarized.A new concept of future optimum design for its equipment is also proposed.
Problems in spray type saturater process for ammonium sulfate production are introduced.Part of ammonium sulfate production processes are optimized so that the saturater service life can be extended,labor intensity can be alleviated and gas quality can be ensured.
To meet the increasingly strict environmental requirement,zero liquid discharge (ZLD) for coking waste water treatment becomes the focus in coking industry research.After Baosteel Zhanjiang put into production,by cutting the raw water amount and by recycling the waste water,the ZLD can be achievable.
Based on the experiences in production,difficulties and problems in pressure measurement for crude benzol distillation under negative pressure are discussed.Comparison is made between advantages and disadvantages for various kinds of pressure measurements under high temperature and negative pressure.Feasible solutions are also given.
The principle of determination of wash oil distillation range by gas chromatography is introduced in this paper.The determination method is discussed.Comparison is made between the gas chromatography method and distillation method.The result shows that the gas chromatography has a quicker determining speed and higher accuracy,which can guide production in a more efficient manner.
This paper introduces the improvement of desulfurization-regeneration and tail gas treatment by adding pre-mixing nozzle and auxiliary facilities.This optimization can reduce the energy consumption of the regenerative air compressor and increase the oxygen availability in the regenerative air.The recycling of the regenerated tail gas to the outlet gas line of the H2S scrubber can minimize environment pollution of the tail gas to the atmosphere.
Steam heater replacing tubular furnace in crude benzol distillation unit is introduced in this paper.Two types of heating are compared in aspects of operation,maintenance,equipment investment and construction cost,etc..The result shows that the steam heater is superior to the tubular furnace in safety performance and environmental level,so it is suitable for the crude benzol distillation unit.
The working principle of ZL type scrubber cleaning agent is studied, which is used for reducing the resistance in H2S scrubber from 2.38kPa down to 0.64kPa so as to avoid shutdown for packings replacement and to have a higher operating efficiency and a significant economic result.
ISSN 1001-3709 CN 21-1164/TQ Sponsor:ACRE Coking & Refractory Engineering Consulting Corporation,MCC Postal Code:8-28
